In the following description of the present disclosure, the case of a cup (glass) for drinking an alcoholic beverage will be described as an example.
In Korean culture, there is a custom in which everyone who attends an event at which an alcoholic beverage is being consumed drinks a full cup of the beverage regardless of their personal drinking capacity (or tolerance to alcohol).
This can put a great deal of social pressure on those with a relatively low drinking capacity, and women in particular, and can even cause health problems.
Therefore, although it would be preferable for everyone to drink according to their own drinking capacity, in order to form a social life or personal relations, many people often drink together using cups, i.e., in units of full cups, and end up drinking too much.
In order to address such a problem, Korean Patent Laid-Open Publication No. 10-2011-0017637 (a capacity-adjustable cup) discloses a structure in which a lift member 120 is inserted into a main body 110 of a cup and is moved up and down, as illustrated in FIG. 1. A driving unit 130 is provided at an outer lower portion of the main body 110 of the cup, and a screw member 133 is inserted through a bottom portion of the main body 110 of the cup and is then coupled to the lift member 120. Then, the screw member 133 is rotated by adjusting a handle 134 to raise or lower the lift member 120.
Therefore, a user can adjust the volume of an alcoholic beverage stored in the main body 110 to a level appropriate to their own drinking capacity by raising and lowering the lift member 120.
However, in order to use such a conventional cup when drinking an alcoholic beverage, a user needs to bring the main body 110 of the cup with the lift member 120 and the driving unit 130 mounted thereon, and this may cause alienation from others who are drinking with the user using another type of cup.
Furthermore, a lead-in groove 122 is formed in the lift member 120 to form a sealing portion 123, and the screw member 133 of the driving unit 130 passes through the bottom portion of the main body 110 to connect with the lift member 120. Therefore, the structure is complicated, and foreign substances easily adhere to the lift member 120 and the driving unit 130, which can be unsanitary and be very disadvantageous in hygiene management.